EP0112666A2 - Vorrangskodiergerät - Google Patents
Vorrangskodiergerät Download PDFInfo
- Publication number
- EP0112666A2 EP0112666A2 EP83307374A EP83307374A EP0112666A2 EP 0112666 A2 EP0112666 A2 EP 0112666A2 EP 83307374 A EP83307374 A EP 83307374A EP 83307374 A EP83307374 A EP 83307374A EP 0112666 A2 EP0112666 A2 EP 0112666A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- data
- error rate
- channels
- transceiver
- chips
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
- H04M11/068—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors using time division multiplex techniques
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J13/00—Code division multiplex systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
- H04L1/0026—Transmission of channel quality indication
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/02—Arrangements for detecting or preventing errors in the information received by diversity reception
- H04L1/04—Arrangements for detecting or preventing errors in the information received by diversity reception using frequency diversity
Definitions
- This invention relates to communication systems and more especially it relates to communication systems comprising a plurality of communication channels, affording or adaptable to afford varying degrees of noise immunity whereby high priority information can be transmitted over a channel having higher noise immunity than a channel carrying lower priority information.
- a communication system comprises a local transceiver for the transmission to and reception from a similar remotely located transceiver of data over N-channels each arranged to carry digital data at, or with reference to a common channel centre frequency, wherein data chips apertaining to each channel are transmitted sequentially in TDM (time division multiplex) mode; wherein at least one of the N-channels is used for the transmission of priority data bits each defined by M chips so that one priority data bit is transmitted each NM data chips and wherein P data bits define each data character so that one priority data character is transmitted each NMP data chips, the local transceiver including means for adapting the number of channels assigned to carry priority data characters in dependence upon a received error rate signal transmitted from the remotely located transceiver indicative of the error rate detected in signals received from the local transceiver, whereby an increase in the detected error rate can be compensated for by a corresponding increase in the channels assigned, and means for transmitting to the remotely located transceiver a transmitted error rate signal indicative of the error rate in data signals
- the local transceiver may include indicator means arranged to be responsive to the received error rate signal transmitted from the remotely located transceiver, for indicating the error rate detected at the remotely located transceiver in data signals received from the local transceiver and switch means operable to change the channels assigned, in accordance with the indication provided by the indicator means.
- the system may be fully automatic and the local transmitter may include control means responsive to the received error rate signal transmitted from the remotely located transceiver for changing in the local transceiver the channels assigned to priority data, in accordance with error rate which obtains at the remote transceiver.
- the system in this latter case is automatically adaptive to provide increased noise immunity when required for the communication of priority data.
- Each transceiver may include a data encoder which includes the control means and which is arranged to feed data defining the N channels to chip store means having a capacity for at least NM data chips, bit store means responsive contemporaneously to M chips in the chip store means, the M chips being spaced one from the other by (N-l) chips, bit detector means responsive to the contents of the bit store means for loading data appertaining to bits into channel store means at addresses determined in accordance with the digital code (0 or 1), of the chips in the bit store means, comparator means responsive to the channel store means and to a character store for providing output data appertaining to a character when correspondence obtains between data bits in the channel store means and data in the character store and an error rate detector responsive to the comparator means for producing the transmitted error rate signal, the control means of the data encoder being responsive to the received error rate signal for adapting the number of channels assigned to carry priority data by assigning data chips corresponding to priority channel chips to a number of other channels.
- Data may be carried for all channels on a common channel carrier frequency by means of AM modulation.
- data for all channels may be carried in the form of phase or frequency modulation referred to a common channel centre frequency or by a combination of AM and FM.
- One of the N channels might normally be assigned for priority data and the remaining N-1 channels may be used individually for separate discrete channel transmissions or in a group or groups for the transmission of pulse coded or delta modulated speach data.
- automatic adaptive compensation will be provided for priority data transmissions comprising assigning other additional channels for the transmission of priority data until the detected error rate is reduced and in the limit all channels may be assigned to priority data.
- a communications system comprises two similar transceivers hereinbefore referred to as the local transceiver and the remotely located transceiver.
- Each transceiver comprises a receiver 1 fed from a receiving aerial 2 and a transmitter 3 arranged to feed the transmitter aerial 4.
- Data may be transmitted utilising any convenient known form of modulation such as amplitude modulation, phase modulation, or frequency modulation, received signals being fed to a data decoder and priority channel controller 5.
- Received data is fed via a data highway 6 to a chip store 7 shown schematically and comprising sufficient storage capacity to store contemporaneously chips appertaining to one bit from each channel. Thus if N channels are used and M chips comprise each data bit the chip store capacity must be at least NM.
- the chip store capacity must be at least 64.
- Channel chips are transmitted in a TDM mode so that chips relating to channel 1 for example are spaced apart by N-1 chips appertaining to the other channels.
- the chip store 7 is arranged to feed eight bit stores, two of which only, referenced 8 and 9 are shown in the drawing.
- One bit store is provided for each channel and is fed from the chip store 7 with chips appertaining to that channel.
- bit store 8 for example is fed via lines 9 with chips appertaining to channel 1 and for simplicity a part only of the chip store 7 is shown schematically and accordingly it will be appreciated that three of the lines 9 only are shown connected to appropriate addresses in the chip store 7.
- Bits appertaining to each channel are differently coded and in channel 1 for example the code 10100101 as shown is indicative of a '1' bit and the inverse of this binary number i.e. 01011010 is indicative of a '0' bit.
- Bit detectors such as bit detectors 10 and 11 are provided in each channel for the recognition of bits appertaining to the channel in which they are connected. Detected bits are fed over the data highways 12 and 13 to channel bit stores 14 and 15.
- the channel bit store 14 serves channel 1 and the channel bit store 15 serves channel 2.
- Six other channel bit stores are provided one for each channel but not shown in the drawing.
- the contents of the bit stores 14 and 15 are compared in comparators 16 and 17 with stored character information held in character stores 18 and 19 respectively. When correspondence obtains between the contents of the channel bit stores and a particular character an appropriate output signal is applied on the output lines 20 and 21 for channel 1 and channel 2 respectively other lines for other channels being provided although not shown.
- characters are defined by eight bits and thus each character is defined by 64 chips. Since however the eight channels are transmitted in TDM mode it will be appreciated that every eigth chip received will relate to channel 1 and so therefore in order to define one character in channel 1, 512 chips must be received by the receiver 1.
- channel 1 Under normal operating conditions if channel 1 is regarded as the priority channel it might be used for the transmission of digitally encoded data whilst channels 2 to 8 may be used in combination, for the transmission of delta modulated or pulse code modulated speach data.
- the received error rate is determined by means of an error rate detector 22 responsive to operation of the comparator 16. Signals indicative of the received error rate are transmitted by the transmitter 3 to be received at the remotely located transceiver (not shown) when the error rate detected by the error rate detector 22 rises above a predetermined limit. This will be sensed at the remotely located transceiver and additional channels will be devoted to the transmission of priority data.
- channel 2 for example is arranged to carry the same data as channel 1 then it will be apparent that the bit store 8 will be receiving the appropriate bit code for twice the normal time. In the limit, all eight channels are devoted to the transmission of priority data and it will be apparent that the bit store 8 will be filled for the whole of the transmission period the appropriate channel 1 bit code.
- the immunity to noise of the priority channel (in this case channel 1) will be improved and it will also be apparent that the system is automatically adaptive, whereby adaptation of the number of channels devoted to priority data is effected automatically in accordance with error rate detection.
- the receiver 1 and the transmitter 3 may take any conventional form including base band amplification or intermediate frequency amplification stages and demodulators and modulators in accordance with the mode of modulation chosen.
- the present invention has the important advantage that maximum use is made of the available effective transmission band width whereby a highly noise immune channel, occupying in effect a wide band width, is not used unless required.
- the effective band width available is normally used for the transmission of a plurality of channels and that only under conditions of high noise and interference will the full available effective band width be devoted to a priority channel.
- the transmitted data bits may be generated using standard line or radio modems e.g. multi-tone FSK, PSK, ASK, etc.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Quality & Reliability (AREA)
- Detection And Prevention Of Errors In Transmission (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8236785 | 1982-12-24 | ||
GB8236785 | 1982-12-24 |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0112666A2 true EP0112666A2 (de) | 1984-07-04 |
Family
ID=10535249
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP83307374A Withdrawn EP0112666A2 (de) | 1982-12-24 | 1983-12-05 | Vorrangskodiergerät |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0112666A2 (de) |
IL (1) | IL70459A0 (de) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0833475A2 (de) * | 1996-09-25 | 1998-04-01 | Canon Kabushiki Kaisha | Modulationsverlaufssteuerung basiert auf festgestellter Fehlerrate |
WO2001045323A2 (en) * | 1999-12-16 | 2001-06-21 | Nokia Corporation | Data transmission apparatus |
-
1983
- 1983-12-05 EP EP83307374A patent/EP0112666A2/de not_active Withdrawn
- 1983-12-15 IL IL70459A patent/IL70459A0/xx unknown
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0833475A2 (de) * | 1996-09-25 | 1998-04-01 | Canon Kabushiki Kaisha | Modulationsverlaufssteuerung basiert auf festgestellter Fehlerrate |
EP0833475A3 (de) * | 1996-09-25 | 2000-01-26 | Canon Kabushiki Kaisha | Modulationsverlaufssteuerung basiert auf festgestellter Fehlerrate |
US6118774A (en) * | 1996-09-25 | 2000-09-12 | Canon Kabushiki Kaisha | Information signal communicating apparatus method and system |
WO2001045323A2 (en) * | 1999-12-16 | 2001-06-21 | Nokia Corporation | Data transmission apparatus |
WO2001045323A3 (en) * | 1999-12-16 | 2002-01-10 | Nokia Networks Oy | Data transmission apparatus |
Also Published As
Publication number | Publication date |
---|---|
IL70459A0 (en) | 1984-03-30 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Designated state(s): DE FR GB NL |
|
17P | Request for examination filed |
Effective date: 19841117 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 19860701 |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: SMITH, DENNIS CLAYTON Inventor name: KING, REGINALD ALFRED |